Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.

NAME

  Forward_Iterators  - A forward-moving iterator that can both read and
  write.

DESCRIPTION

  For a complete discussion of iterators, see the Iterators section of this
  reference.

  Iterators are a generalization of pointers that allow a C++ program to
  uniformly interact with different data structures.  Forward iterators are
  forward moving, and have the ability to both read and write data.  These
  iterators satisfy the requirements listed below.

KEY TO ITERATOR REQUIREMENTS

  The following key pertains to the iterator requirements listed below:

  a and b   values of type X

  n   value of distance type

  u, Distance, tmp and m   identifiers

  r   value of type X&

  t   value of type T

REQUIREMENTS FOR FORWARD ITERATORS

  The following expressions must be valid for forward iterators:

  X u   u might have a singular value

  X()   X() might be singular

  X(a)   copy constructor, a == X(a).

  X u(a)   copy constructor, u == a

  X u = a   assignment, u == a

  a == b, a != b   return value convertible to bool

  *a   return value convertible to T&

  a->m   equivalent to (*a).m

  ++r   returns X&

  r++   return value convertible to const X&

  *r++   returns T&

  Forward iterators have the condition that a == b implies *a == *b.

  There are no restrictions on the number of passes an algorithm may make
  through the structure.

SEE ALSO

  Iterators, Bidirectional Iterators

STANDARDS CONFORMANCE

  ANSI X3J16/ISO WG21 Joint C++ Committee



privacy and legal statement